[Intel-wired-lan] [PATCH v2 iwl-net 6/8] ice: improve updating ice_{t, r}x_ring::xsk_pool
Maciej Fijalkowski
maciej.fijalkowski at intel.com
Tue Jun 4 10:52:16 UTC 2024
On Fri, May 31, 2024 at 04:49:05PM -0700, Nelson, Shannon wrote:
> On 5/29/2024 4:23 AM, Maciej Fijalkowski wrote:
> >
> > xsk_buff_pool pointers that ice ring structs hold are updated via
> > ndo_bpf that is executed in process context while it can be read by
> > remote CPU at the same time within NAPI poll. Use synchronize_net()
> > after pointer update and {READ,WRITE}_ONCE() when working with mentioned
> > pointer.
> >
> > Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
> > Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski at intel.com>
> > ---
> > drivers/net/ethernet/intel/ice/ice.h | 6 +-
> > drivers/net/ethernet/intel/ice/ice_base.c | 4 +-
> > drivers/net/ethernet/intel/ice/ice_main.c | 2 +-
> > drivers/net/ethernet/intel/ice/ice_txrx.c | 4 +-
> > drivers/net/ethernet/intel/ice/ice_xsk.c | 78 ++++++++++++++---------
> > drivers/net/ethernet/intel/ice/ice_xsk.h | 4 +-
> > 6 files changed, 59 insertions(+), 39 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
> > index da8c8afebc93..701a61d791dd 100644
> > --- a/drivers/net/ethernet/intel/ice/ice.h
> > +++ b/drivers/net/ethernet/intel/ice/ice.h
> > @@ -771,12 +771,12 @@ static inline struct xsk_buff_pool *ice_get_xp_from_qid(struct ice_vsi *vsi,
> > * Returns a pointer to xsk_buff_pool structure if there is a buffer pool
> > * present, NULL otherwise.
> > */
> > -static inline struct xsk_buff_pool *ice_xsk_pool(struct ice_rx_ring *ring)
> > +static inline void ice_xsk_pool(struct ice_rx_ring *ring)
>
> Since this patch is changing the logic here you mighht want to change the
> name of the function. Instead of getting a pointer with no side effects it
> is now doing something, so a better name might be ice_set_xsk_pool() to
> reflect the resulting side effect.
Makes sense, plus the function description needs some adjustment. Will fix
on v3.
>
> sln
>
> > {
> > struct ice_vsi *vsi = ring->vsi;
> > u16 qid = ring->q_index;
> >
> > - return ice_get_xp_from_qid(vsi, qid);
> > + WRITE_ONCE(ring->xsk_pool, ice_get_xp_from_qid(vsi, qid));
> > }
> >
> > /**
> > @@ -801,7 +801,7 @@ static inline void ice_tx_xsk_pool(struct ice_vsi *vsi, u16 qid)
> > if (!ring)
> > return;
> >
> > - ring->xsk_pool = ice_get_xp_from_qid(vsi, qid);
> > + WRITE_ONCE(ring->xsk_pool, ice_get_xp_from_qid(vsi, qid));
> > }
> >
> > /**
> > diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c
> > index 5d396c1a7731..f3dfce136106 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_base.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_base.c
> > @@ -536,7 +536,7 @@ static int ice_vsi_cfg_rxq(struct ice_rx_ring *ring)
> > return err;
> > }
> >
> > - ring->xsk_pool = ice_xsk_pool(ring);
> > + ice_xsk_pool(ring);
> > if (ring->xsk_pool) {
> > xdp_rxq_info_unreg(&ring->xdp_rxq);
> >
> > @@ -597,7 +597,7 @@ static int ice_vsi_cfg_rxq(struct ice_rx_ring *ring)
> > return 0;
> > }
> >
> > - ok = ice_alloc_rx_bufs_zc(ring, num_bufs);
> > + ok = ice_alloc_rx_bufs_zc(ring, ring->xsk_pool, num_bufs);
> > if (!ok) {
> > u16 pf_q = ring->vsi->rxq_map[ring->q_index];
> >
> > diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
> > index 1b61ca3a6eb6..15a6805ac2a1 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_main.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> > @@ -2946,7 +2946,7 @@ static void ice_vsi_rx_napi_schedule(struct ice_vsi *vsi)
> > ice_for_each_rxq(vsi, i) {
> > struct ice_rx_ring *rx_ring = vsi->rx_rings[i];
> >
> > - if (rx_ring->xsk_pool)
> > + if (READ_ONCE(rx_ring->xsk_pool))
> > napi_schedule(&rx_ring->q_vector->napi);
> > }
> > }
> > diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
> > index 8bb743f78fcb..f4b2b1bca234 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_txrx.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
> > @@ -1523,7 +1523,7 @@ int ice_napi_poll(struct napi_struct *napi, int budget)
> > ice_for_each_tx_ring(tx_ring, q_vector->tx) {
> > bool wd;
> >
> > - if (tx_ring->xsk_pool)
> > + if (READ_ONCE(tx_ring->xsk_pool))
> > wd = ice_xmit_zc(tx_ring);
> > else if (ice_ring_is_xdp(tx_ring))
> > wd = true;
> > @@ -1556,7 +1556,7 @@ int ice_napi_poll(struct napi_struct *napi, int budget)
> > * comparison in the irq context instead of many inside the
> > * ice_clean_rx_irq function and makes the codebase cleaner.
> > */
> > - cleaned = rx_ring->xsk_pool ?
> > + cleaned = READ_ONCE(rx_ring->xsk_pool) ?
> > ice_clean_rx_irq_zc(rx_ring, budget_per_ring) :
> > ice_clean_rx_irq(rx_ring, budget_per_ring);
> > work_done += cleaned;
> > diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
> > index 8c5006f37310..693f0e3a37ce 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_xsk.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
> > @@ -250,6 +250,8 @@ static int ice_qp_ena(struct ice_vsi *vsi, u16 q_idx)
> > ice_qvec_toggle_napi(vsi, q_vector, true);
> > ice_qvec_ena_irq(vsi, q_vector);
> >
> > + /* make sure NAPI sees updated ice_{t,x}_ring::xsk_pool */
> > + synchronize_net();
> > netif_tx_start_queue(netdev_get_tx_queue(vsi->netdev, q_idx));
> > netif_carrier_on(vsi->netdev);
> > clear_bit(ICE_CFG_BUSY, vsi->state);
> > @@ -461,6 +463,7 @@ static u16 ice_fill_rx_descs(struct xsk_buff_pool *pool, struct xdp_buff **xdp,
> > /**
> > * __ice_alloc_rx_bufs_zc - allocate a number of Rx buffers
> > * @rx_ring: Rx ring
> > + * @xsk_pool: XSK buffer pool to pick buffers to be filled by HW
> > * @count: The number of buffers to allocate
> > *
> > * Place the @count of descriptors onto Rx ring. Handle the ring wrap
> > @@ -469,7 +472,8 @@ static u16 ice_fill_rx_descs(struct xsk_buff_pool *pool, struct xdp_buff **xdp,
> > *
> > * Returns true if all allocations were successful, false if any fail.
> > */
> > -static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
> > +static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring,
> > + struct xsk_buff_pool *xsk_pool, u16 count)
> > {
> > u32 nb_buffs_extra = 0, nb_buffs = 0;
> > union ice_32b_rx_flex_desc *rx_desc;
> > @@ -481,8 +485,7 @@ static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
> > xdp = ice_xdp_buf(rx_ring, ntu);
> >
> > if (ntu + count >= rx_ring->count) {
> > - nb_buffs_extra = ice_fill_rx_descs(rx_ring->xsk_pool, xdp,
> > - rx_desc,
> > + nb_buffs_extra = ice_fill_rx_descs(xsk_pool, xdp, rx_desc,
> > rx_ring->count - ntu);
> > if (nb_buffs_extra != rx_ring->count - ntu) {
> > ntu += nb_buffs_extra;
> > @@ -495,7 +498,7 @@ static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
> > ice_release_rx_desc(rx_ring, 0);
> > }
> >
> > - nb_buffs = ice_fill_rx_descs(rx_ring->xsk_pool, xdp, rx_desc, count);
> > + nb_buffs = ice_fill_rx_descs(xsk_pool, xdp, rx_desc, count);
> >
> > ntu += nb_buffs;
> > if (ntu == rx_ring->count)
> > @@ -511,6 +514,7 @@ static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
> > /**
> > * ice_alloc_rx_bufs_zc - allocate a number of Rx buffers
> > * @rx_ring: Rx ring
> > + * @xsk_pool: XSK buffer pool to pick buffers to be filled by HW
> > * @count: The number of buffers to allocate
> > *
> > * Wrapper for internal allocation routine; figure out how many tail
> > @@ -518,7 +522,8 @@ static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
> > *
> > * Returns true if all calls to internal alloc routine succeeded
> > */
> > -bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
> > +bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring,
> > + struct xsk_buff_pool *xsk_pool, u16 count)
> > {
> > u16 rx_thresh = ICE_RING_QUARTER(rx_ring);
> > u16 leftover, i, tail_bumps;
> > @@ -527,9 +532,9 @@ bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
> > leftover = count - (tail_bumps * rx_thresh);
> >
> > for (i = 0; i < tail_bumps; i++)
> > - if (!__ice_alloc_rx_bufs_zc(rx_ring, rx_thresh))
> > + if (!__ice_alloc_rx_bufs_zc(rx_ring, xsk_pool, rx_thresh))
> > return false;
> > - return __ice_alloc_rx_bufs_zc(rx_ring, leftover);
> > + return __ice_alloc_rx_bufs_zc(rx_ring, xsk_pool, leftover);
> > }
> >
> > /**
> > @@ -650,7 +655,7 @@ static u32 ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring)
> > if (xdp_ring->next_to_clean >= cnt)
> > xdp_ring->next_to_clean -= cnt;
> > if (xsk_frames)
> > - xsk_tx_completed(xdp_ring->xsk_pool, xsk_frames);
> > + xsk_tx_completed(READ_ONCE(xdp_ring->xsk_pool), xsk_frames);
> >
> > return completed_frames;
> > }
> > @@ -702,7 +707,8 @@ static int ice_xmit_xdp_tx_zc(struct xdp_buff *xdp,
> > dma_addr_t dma;
> >
> > dma = xsk_buff_xdp_get_dma(xdp);
> > - xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma, size);
> > + xsk_buff_raw_dma_sync_for_device(READ_ONCE(xdp_ring->xsk_pool),
> > + dma, size);
> >
> > tx_buf->xdp = xdp;
> > tx_buf->type = ICE_TX_BUF_XSK_TX;
> > @@ -760,7 +766,8 @@ ice_run_xdp_zc(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp,
> > err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
> > if (!err)
> > return ICE_XDP_REDIR;
> > - if (xsk_uses_need_wakeup(rx_ring->xsk_pool) && err == -ENOBUFS)
> > + if (xsk_uses_need_wakeup(READ_ONCE(rx_ring->xsk_pool)) &&
> > + err == -ENOBUFS)
> > result = ICE_XDP_EXIT;
> > else
> > result = ICE_XDP_CONSUMED;
> > @@ -829,8 +836,8 @@ ice_add_xsk_frag(struct ice_rx_ring *rx_ring, struct xdp_buff *first,
> > */
> > int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
> > {
> > + struct xsk_buff_pool *xsk_pool = READ_ONCE(rx_ring->xsk_pool);
> > unsigned int total_rx_bytes = 0, total_rx_packets = 0;
> > - struct xsk_buff_pool *xsk_pool = rx_ring->xsk_pool;
> > u32 ntc = rx_ring->next_to_clean;
> > u32 ntu = rx_ring->next_to_use;
> > struct xdp_buff *first = NULL;
> > @@ -942,7 +949,8 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
> > rx_ring->next_to_clean = ntc;
> > entries_to_alloc = ICE_RX_DESC_UNUSED(rx_ring);
> > if (entries_to_alloc > ICE_RING_QUARTER(rx_ring))
> > - failure |= !ice_alloc_rx_bufs_zc(rx_ring, entries_to_alloc);
> > + failure |= !ice_alloc_rx_bufs_zc(rx_ring, xsk_pool,
> > + entries_to_alloc);
> >
> > ice_finalize_xdp_rx(xdp_ring, xdp_xmit, 0);
> > ice_update_rx_ring_stats(rx_ring, total_rx_packets, total_rx_bytes);
> > @@ -965,17 +973,19 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
> > /**
> > * ice_xmit_pkt - produce a single HW Tx descriptor out of AF_XDP descriptor
> > * @xdp_ring: XDP ring to produce the HW Tx descriptor on
> > + * @xsk_pool: XSK buffer pool to pick buffers to be consumed by HW
> > * @desc: AF_XDP descriptor to pull the DMA address and length from
> > * @total_bytes: bytes accumulator that will be used for stats update
> > */
> > -static void ice_xmit_pkt(struct ice_tx_ring *xdp_ring, struct xdp_desc *desc,
> > +static void ice_xmit_pkt(struct ice_tx_ring *xdp_ring,
> > + struct xsk_buff_pool *xsk_pool, struct xdp_desc *desc,
> > unsigned int *total_bytes)
> > {
> > struct ice_tx_desc *tx_desc;
> > dma_addr_t dma;
> >
> > - dma = xsk_buff_raw_get_dma(xdp_ring->xsk_pool, desc->addr);
> > - xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma, desc->len);
> > + dma = xsk_buff_raw_get_dma(xsk_pool, desc->addr);
> > + xsk_buff_raw_dma_sync_for_device(xsk_pool, dma, desc->len);
> >
> > tx_desc = ICE_TX_DESC(xdp_ring, xdp_ring->next_to_use++);
> > tx_desc->buf_addr = cpu_to_le64(dma);
> > @@ -988,10 +998,13 @@ static void ice_xmit_pkt(struct ice_tx_ring *xdp_ring, struct xdp_desc *desc,
> > /**
> > * ice_xmit_pkt_batch - produce a batch of HW Tx descriptors out of AF_XDP descriptors
> > * @xdp_ring: XDP ring to produce the HW Tx descriptors on
> > + * @xsk_pool: XSK buffer pool to pick buffers to be consumed by HW
> > * @descs: AF_XDP descriptors to pull the DMA addresses and lengths from
> > * @total_bytes: bytes accumulator that will be used for stats update
> > */
> > -static void ice_xmit_pkt_batch(struct ice_tx_ring *xdp_ring, struct xdp_desc *descs,
> > +static void ice_xmit_pkt_batch(struct ice_tx_ring *xdp_ring,
> > + struct xsk_buff_pool *xsk_pool,
> > + struct xdp_desc *descs,
> > unsigned int *total_bytes)
> > {
> > u16 ntu = xdp_ring->next_to_use;
> > @@ -1001,8 +1014,8 @@ static void ice_xmit_pkt_batch(struct ice_tx_ring *xdp_ring, struct xdp_desc *de
> > loop_unrolled_for(i = 0; i < PKTS_PER_BATCH; i++) {
> > dma_addr_t dma;
> >
> > - dma = xsk_buff_raw_get_dma(xdp_ring->xsk_pool, descs[i].addr);
> > - xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma, descs[i].len);
> > + dma = xsk_buff_raw_get_dma(xsk_pool, descs[i].addr);
> > + xsk_buff_raw_dma_sync_for_device(xsk_pool, dma, descs[i].len);
> >
> > tx_desc = ICE_TX_DESC(xdp_ring, ntu++);
> > tx_desc->buf_addr = cpu_to_le64(dma);
> > @@ -1018,21 +1031,24 @@ static void ice_xmit_pkt_batch(struct ice_tx_ring *xdp_ring, struct xdp_desc *de
> > /**
> > * ice_fill_tx_hw_ring - produce the number of Tx descriptors onto ring
> > * @xdp_ring: XDP ring to produce the HW Tx descriptors on
> > + * @xsk_pool: XSK buffer pool to pick buffers to be consumed by HW
> > * @descs: AF_XDP descriptors to pull the DMA addresses and lengths from
> > * @nb_pkts: count of packets to be send
> > * @total_bytes: bytes accumulator that will be used for stats update
> > */
> > -static void ice_fill_tx_hw_ring(struct ice_tx_ring *xdp_ring, struct xdp_desc *descs,
> > - u32 nb_pkts, unsigned int *total_bytes)
> > +static void ice_fill_tx_hw_ring(struct ice_tx_ring *xdp_ring,
> > + struct xsk_buff_pool *xsk_pool,
> > + struct xdp_desc *descs, u32 nb_pkts,
> > + unsigned int *total_bytes)
> > {
> > u32 batched, leftover, i;
> >
> > batched = ALIGN_DOWN(nb_pkts, PKTS_PER_BATCH);
> > leftover = nb_pkts & (PKTS_PER_BATCH - 1);
> > for (i = 0; i < batched; i += PKTS_PER_BATCH)
> > - ice_xmit_pkt_batch(xdp_ring, &descs[i], total_bytes);
> > + ice_xmit_pkt_batch(xdp_ring, xsk_pool, &descs[i], total_bytes);
> > for (; i < batched + leftover; i++)
> > - ice_xmit_pkt(xdp_ring, &descs[i], total_bytes);
> > + ice_xmit_pkt(xdp_ring, xsk_pool, &descs[i], total_bytes);
> > }
> >
> > /**
> > @@ -1043,7 +1059,8 @@ static void ice_fill_tx_hw_ring(struct ice_tx_ring *xdp_ring, struct xdp_desc *d
> > */
> > bool ice_xmit_zc(struct ice_tx_ring *xdp_ring)
> > {
> > - struct xdp_desc *descs = xdp_ring->xsk_pool->tx_descs;
> > + struct xsk_buff_pool *xsk_pool = READ_ONCE(xdp_ring->xsk_pool);
> > + struct xdp_desc *descs = xsk_pool->tx_descs;
> > u32 nb_pkts, nb_processed = 0;
> > unsigned int total_bytes = 0;
> > int budget;
> > @@ -1057,25 +1074,26 @@ bool ice_xmit_zc(struct ice_tx_ring *xdp_ring)
> > budget = ICE_DESC_UNUSED(xdp_ring);
> > budget = min_t(u16, budget, ICE_RING_QUARTER(xdp_ring));
> >
> > - nb_pkts = xsk_tx_peek_release_desc_batch(xdp_ring->xsk_pool, budget);
> > + nb_pkts = xsk_tx_peek_release_desc_batch(xsk_pool, budget);
> > if (!nb_pkts)
> > return true;
> >
> > if (xdp_ring->next_to_use + nb_pkts >= xdp_ring->count) {
> > nb_processed = xdp_ring->count - xdp_ring->next_to_use;
> > - ice_fill_tx_hw_ring(xdp_ring, descs, nb_processed, &total_bytes);
> > + ice_fill_tx_hw_ring(xdp_ring, xsk_pool, descs, nb_processed,
> > + &total_bytes);
> > xdp_ring->next_to_use = 0;
> > }
> >
> > - ice_fill_tx_hw_ring(xdp_ring, &descs[nb_processed], nb_pkts - nb_processed,
> > - &total_bytes);
> > + ice_fill_tx_hw_ring(xdp_ring, xsk_pool, &descs[nb_processed],
> > + nb_pkts - nb_processed, &total_bytes);
> >
> > ice_set_rs_bit(xdp_ring);
> > ice_xdp_ring_update_tail(xdp_ring);
> > ice_update_tx_ring_stats(xdp_ring, nb_pkts, total_bytes);
> >
> > - if (xsk_uses_need_wakeup(xdp_ring->xsk_pool))
> > - xsk_set_tx_need_wakeup(xdp_ring->xsk_pool);
> > + if (xsk_uses_need_wakeup(xsk_pool))
> > + xsk_set_tx_need_wakeup(xsk_pool);
> >
> > return nb_pkts < budget;
> > }
> > @@ -1108,7 +1126,7 @@ ice_xsk_wakeup(struct net_device *netdev, u32 queue_id,
> >
> > ring = vsi->rx_rings[queue_id]->xdp_ring;
> >
> > - if (!ring->xsk_pool)
> > + if (!READ_ONCE(ring->xsk_pool))
> > return -EINVAL;
> >
> > /* The idea here is that if NAPI is running, mark a miss, so
> > diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.h b/drivers/net/ethernet/intel/ice/ice_xsk.h
> > index 6fa181f080ef..4cd2d62a0836 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_xsk.h
> > +++ b/drivers/net/ethernet/intel/ice/ice_xsk.h
> > @@ -22,7 +22,8 @@ int ice_xsk_pool_setup(struct ice_vsi *vsi, struct xsk_buff_pool *pool,
> > u16 qid);
> > int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget);
> > int ice_xsk_wakeup(struct net_device *netdev, u32 queue_id, u32 flags);
> > -bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count);
> > +bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring,
> > + struct xsk_buff_pool *xsk_pool, u16 count);
> > bool ice_xsk_any_rx_ring_ena(struct ice_vsi *vsi);
> > void ice_xsk_clean_rx_ring(struct ice_rx_ring *rx_ring);
> > void ice_xsk_clean_xdp_ring(struct ice_tx_ring *xdp_ring);
> > @@ -51,6 +52,7 @@ ice_clean_rx_irq_zc(struct ice_rx_ring __always_unused *rx_ring,
> >
> > static inline bool
> > ice_alloc_rx_bufs_zc(struct ice_rx_ring __always_unused *rx_ring,
> > + struct xsk_buff_pool __always_unused *xsk_pool,
> > u16 __always_unused count)
> > {
> > return false;
> > --
> > 2.34.1
> >
> >
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